Force root/root as names for uid0/gid0 instead of using the system
names. This helps make packed download tarballs more reproducible

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
--- a/src/create.c
+++ b/src/create.c
@@ -545,12 +545,8 @@ write_gnu_long_link (struct tar_stat_inf
   char *tmpname;
 
   header = start_private_header ("././@LongLink", size, 0);
-  uid_to_uname (0, &tmpname);
-  UNAME_TO_CHARS (tmpname, header->header.uname);
-  free (tmpname);
-  gid_to_gname (0, &tmpname);
-  GNAME_TO_CHARS (tmpname, header->header.gname);
-  free (tmpname);
+  UNAME_TO_CHARS ("root", header->header.uname);
+  GNAME_TO_CHARS ("root", header->header.gname);
 
   strcpy (header->buffer + offsetof (struct posix_header, magic),
 	  OLDGNU_MAGIC);
